Pentax 645, no in-finder display, looking for hints / solution

[Hassasin]

On my Pentax 645 (original) everything seems to work fine with sole exception of no display inside viewfinder, so far no button / mode combination triggers anything.

Top LCD is working fine, all functions appear to work as well, pressing LED button on top does not turn finder display on, top LCD does get illumination when engaged with "O" button. Tried two lenses to same result. Auto modes work, P mode is fine, manual modes also work fine.

In grip batteries are new. The only thing I have not done yet is the internal battery replacement, which technically is not supposed to affect the in-finder display, but maybe there is relation ??

Has anyone run into similar issue ?

 

[Hassasin]

Just bumping it up with hopes someone new sees this thread.

 

[benveniste]

The finder display in a Pentax 645 is purely a optical path. My guess is that the mirror is stuck in the "up" position or that the focusing screen is not correctly seated.

 

[pentaxuser]

OP you might want to join the PentaxForums group where by definition a lot more of P645 users are. Just be warned that such users now seem to be small group as well with the advent of Pentax MF digitals

pentaxuser

 

[Hassasin]

LED finder display in P645 is not a mirror image of anything or "optical path", it is direct LED display in dedicated cut out off to side of the screen. It blanks out for the time mirror is momentarily up. If there were ANY optical paths to speak of, I'd still see at least a red glow in total darkness looking inside mirror box. Camera works outside of the finder display. I'm suspecting electrical path to LED block but just got service manual and so far I can't even locate the LED block within the blow up diagram. LCD does get its led blacklight but that is a different unit.

 

[Hassasin]

OP you might want to join the PentaxForums group where by definition a lot more of P645 users are. Just be warned that such users now seem to be small group as well with the advent of Pentax MF digitals

pentaxuser

I am actually registered there, will give it a go. Have two P645s and one started doing this, all else still appears fine in both.

 

[pentaxuser]

I am actually registered there, will give it a go. Have two P645s and one started doing this, all else still appears fine in both.

I hope you find a P645 user or users who knows or know about this problem and the fix or fixes for it

pentaxuser